Impedance matching circuit, power supply apparatus, and plasma processing equipment including same

Abstract

An impedance matching circuit, which is provided for quick impedance matching, a power supply apparatus, and a plasma processing equipment including the same are provided. The impedance matching circuit includes a parallel capacitor array connected to a radio frequency (RF) power supply to generate a RF signal, and a series capacitor array connected to the RF power supply in series, wherein the parallel capacitor array or the series capacitor array includes a mechanical vacuum variable capacitor and an electrical switch capacitor module connected to the mechanical vacuum variable capacitor in parallel.

What is claimed is: 
     
         1 . An impedance matching circuit comprising:
 a parallel capacitor array connected to a radio frequency (RF) power supply to generate a RF signal; and   a series capacitor array connected to the RF power supply in series,   wherein the parallel capacitor array or the series capacitor array comprises a mechanical vacuum variable capacitor and an electrical switch capacitor module connected to the mechanical vacuum variable capacitor in parallel.   
     
     
         2 . The impedance matching circuit of  claim 1 , wherein the parallel capacitor array comprises:
 a parallel mechanical vacuum variable capacitor; and   a plurality of parallel electrical switch capacitor modules connected to the parallel mechanical vacuum variable capacitor in parallel,   wherein each of the parallel electrical switch capacitor modules comprises:   a parallel fixed capacitor having a fixed capacitance; and   a parallel switch connected to the parallel fixed capacitor in series.   
     
     
         3 . The impedance matching circuit of  claim 2 , wherein the parallel mechanical vacuum variable capacitor has a capacitance larger than the parallel fixed capacitor. 
     
     
         4 . The impedance matching circuit of  claim 1 , wherein the series capacitor array comprises:
 a series mechanical vacuum variable capacitor; and   a plurality of series electrical switch capacitor modules connected to the series mechanical vacuum variable capacitor in parallel,   wherein each of the plurality of the series electrical switch capacitor modules comprises:   a series fixed capacitor having a fixed capacitance; and   a series switch connected to the series fixed capacitor in series.   
     
     
         5 . The impedance matching circuit of  claim 4 , wherein the series mechanical vacuum variable capacitor has a capacitance larger than the series fixed capacitor. 
     
     
         6 . A power supply apparatus of plasma processing equipment, the power supply apparatus comprising:
 a first power supply part comprising a first radio frequency (RF) power supply configured to generate a first RF signal, a first matching circuit connected to the first RF power supply, and a first power transfer circuit configured to transfer the first RF signal to a plasma load;   a second power supply part comprising a second RF power supply configured to generate a second RF signal, a second matching circuit connected to the second RF power supply, and a second power transfer circuit configured to transfer the second RF signal to the plasma load; and   a decoupling part configured to remove interference between the first power supply part and the second power supply part,   wherein each of the first matching circuit and the second matching circuit comprises a mechanical vacuum variable capacitor and a plurality of electrical switch capacitor modules connected to the mechanical vacuum variable capacitor in parallel.   
     
     
         7 . The power supply apparatus of  claim 6 , wherein the decoupling part comprises:
 a first decoupling inductor connected to the first matching circuit and the first power transfer circuit while being located therebetween;   a second decoupling inductor connected to the first matching circuit and the first power transfer circuit while being located therebetween and coupled to the first decoupling inductor in a mutually magnetic coupling manner; and   a decoupling capacitor connected to the first matching circuit and the second matching circuit.   
     
     
         8 . The power supply apparatus of  claim 6 , wherein the first matching circuit comprises:
 a first parallel capacitor array coupled to the first RF power supply and an earthing, and comprising a plurality of capacitors connected to each other in parallel; and   a first series capacitor array coupled to the first RF power supply and the decoupling part, and comprising a plurality of capacitors connected to the parallel capacitor array in series, and   the second matching circuit comprises:   a second parallel capacitor array connected to the second RF power supply and an earthing, and comprising a plurality of capacitors connected to each other in parallel; and   a second series capacitor array connected to the second RF power supply and the power transfer circuit, and comprising a plurality of capacitors connected to the second parallel capacitor array in series.   
     
     
         9 . The power supply apparatus of  claim 8 , wherein the first parallel capacitor array comprises:
 a parallel mechanical vacuum variable capacitor; and   a plurality of parallel electrical switch capacitor modules connected to the parallel mechanical vacuum variable capacitor in parallel, and   the first series capacitor array comprises:   a series mechanical vacuum variable capacitor; and   a plurality of series electrical switch capacitor modules connected to the series mechanical vacuum variable capacitor in parallel.   
     
     
         10 . The power supply apparatus of  claim 9 , wherein each of the parallel electrical switch capacitor modules comprises:
 a parallel fixed capacitor having a fixed capacitance; and   a parallel switch connected to the parallel fixed capacitor in series, and   each of the series electrical switch capacitor modules comprises:   a series fixed capacitor having a fixed capacitance; and   a series switch connected to the series fixed capacitor in series.   
     
     
         11 . The power supply apparatus of  claim 10 , wherein the parallel mechanical vacuum variable capacitor has a capacitance larger than the parallel fixed capacitor, and
 the series mechanical vacuum variable capacitor has a capacitance larger than the series fixed capacitor.   
     
     
         12 . The power supply apparatus of  claim 6 , wherein the first matching circuit comprises:
 a fixed shunt capacitor coupled to the first RF power supply and an earthing;   a first series capacitor array coupled to the first RF power supply and the fixed shunt capacitor, and comprising a plurality of capacitors connected to each other in parallel; and   a second series capacitor array coupled to the fixed shunt capacitor and the decoupling part, and comprising a plurality of capacitors connected to each other in parallel.   
     
     
         13 . The power supply apparatus of  claim 12 , wherein the first series capacitor comprises a first mechanical vacuum variable capacitor and a plurality of first parallel electrical switch capacitor modules connected to the first mechanical vacuum variable capacitor in parallel, and
 the second series capacitor comprises a second mechanical vacuum variable capacitor and a plurality of second parallel electrical switch capacitor modules connected to the second mechanical vacuum variable capacitor in parallel,   wherein each of the first parallel electrical switch capacitor modules comprises a first fixed capacitor and a first switch connected to the first fixed capacitor in series, and   each of the second parallel electrical switch capacitor modules comprises a second fixed capacitor and a second switch connected to the second fixed capacitor in series.   
     
     
         14 . Plasma processing equipment comprising:
 a processing chamber configured to perform processing with respect to a substrate; and   a power supply apparatus configured to supply power to the processing chamber to generate plasma,   wherein the power supply apparatus comprises:   a first power supply part comprising a first radio frequency (RF) power supply configured to generate a first RF signal, a first matching circuit connected to the first RF power supply, and a first power transfer circuit configured to transfer the first RF signal to a plasma load;   a second power supply part comprising a second RF power supply configured to generate a second RF signal, a second matching circuit connected to the second RF power supply, and a second power transfer circuit configured to transfer the second RF signal to the plasma load; and   a decoupling part configured to remove interference between the first power supply part and the second power supply part,   wherein each of the first matching circuit and the second matching circuit comprises a mechanical vacuum variable capacitor and a plurality of electrical variable capacitor modules connected to the mechanical vacuum variable capacitor in parallel, and   when a process condition of the processing chamber is changed, as the electrical variable capacitor modules are controlled while a capacitance of the mechanical vacuum variable capacitor is fixed, an impedance of each of the first matching circuit and the second matching circuit is adjusted.   
     
     
         15 . The plasma processing equipment of  claim 14 , wherein the first matching circuit comprises:
 a first parallel capacitor array comprising a plurality of capacitors connected to each other in parallel; and   a first series capacitor array comprising a plurality of capacitors connected to the parallel capacitor array in series, and   the second matching circuit comprises:   a second parallel capacitor array comprising a plurality of capacitors connected to each other in parallel; and   a second series capacitor array comprising a plurality of capacitors connected to the second parallel capacitor array in series.   
     
     
         16 . The plasma processing equipment of  claim 15 , wherein the first parallel capacitor array comprises:
 a parallel mechanical vacuum variable capacitor; and   a plurality of parallel electrical switch capacitor modules connected to the parallel mechanical vacuum variable capacitor in parallel, and   the first series capacitor array comprises:   a series mechanical vacuum variable capacitor; and   a plurality of series electrical switch capacitor modules connected to the series mechanical vacuum variable capacitor in parallel.   
     
     
         17 . The plasma processing equipment of  claim 16 , wherein each of the parallel electrical switch capacitor modules comprises:
 a parallel fixed capacitor having a fixed capacitance; and   a parallel switch connected to the parallel fixed capacitor in series,   each of the series electrical switch capacitor modules comprises:   a series fixed capacitor having a fixed capacitance; and   a series switch connected to the series fixed capacitor in series,   the parallel mechanical vacuum variable capacitor has a capacitance larger than the parallel fixed capacitor, and   the series mechanical vacuum variable capacitor has a capacitance larger than the series fixed capacitor.   
     
     
         18 . The plasma processing equipment of  claim 17 , wherein the capacitance of each of the parallel mechanical vacuum variable capacitor and the series mechanical vacuum variable capacitor is adjusted to a preset value,
 the preset value is determined by a type, flux, pressure of process gas, or supplied power of the plasma processing equipment, and   when a process condition of the processing chamber is changed, with the capacitance of each of the parallel mechanical vacuum variable capacitor and the series mechanical vacuum variable capacitor fixed to the preset value, switching control of the parallel electrical switch capacitor modules and the series electrical switch capacitor modules allows impedance matching.   
     
     
         19 . A substrate processing method, which is performed by a plasma processing equipment according to  claim 14 , the substrate processing method comprising:
 adjusting an impedance of each of the first matching circuit and the second matching circuit; and   performing processing with respect to the substrate when the impedance adjustment is completed,   wherein the adjusting of the impedance comprises:   adjusting a capacitance of the mechanical vacuum variable capacitor to a preset value;   measuring an input impedance of each of the first matching circuit and the second matching circuit;   determining whether a reflecting coefficient from the plasma load is larger than a reference reflecting coefficient or not;   measuring an impedance of the plasma load when the reflecting coefficient is larger than the reference reflecting coefficient; and   adjusting a capacitance of each of the electrical variable capacitor modules by switch on-off control of the plurality of electrical variable capacitor modules on the basis of the impedance of the plasma load.   
     
     
         20 . The substrate processing method of  claim 19 , wherein the adjusting of the capacitance of each of the electrical variable capacitor modules comprises:
 calculating an impedance adjustment value on the basis of the impedance of the plasma load; and   turning on a switch of an electrical variable capacitor module having a capacitance corresponding to the impedance adjustment value, among the electrical variable capacitor modules.